"Attaching one of these lenses to a tally box changes the way it detects items at its target location.

A box with the Unbound lens examines loose items at the location rather than items in a container.

The Yield lens reveals to the box the items that may be dropped by the targeted block. (Both standard results and those possible using a tool with the silk touch enchant are considered.) This may be a good way to output a signal only when the target contains a specific block."